Stevens, C. Edward College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.
Last reviewed:March 2019
Show previous versions
- Pancreas and biliary system
- Nerve and endocrine tissues
- Importance of indigenous bacteria
- Links to Primary Literature
- Additional Readings
A set of structures and organs in which food substances are digested. The vertebrate digestive system consists of the digestive tract (alimentary canal) and ancillary organs that serve for the acquisition of food and the assimilation of nutrients required for energy, growth, maintenance, and reproduction. Food is ingested, reduced to particles, mixed with digestive fluids and enzymes, and propelled through the digestive tract. Enzymes produced by the host animal and microbes indigenous to the digestive tract destroy harmful agents and convert food into a limited number of nutrients, which are selectively absorbed. Some characteristics of the vertebrate digestive system are common to all classes of vertebrates and appear to have been conserved in their evolution. In other aspects, the digestive systems of vertebrates show numerous structural and functional adaptations to their diet, habitat, and other physiological characteristics (Fig. 1). Carnivores, which feed exclusively on other animals, and species that feed on plant concentrates (seeds, fruit, nectar, and pollen) tend to have the shortest and simplest digestive tract. The digestive tract tends to be more complex in omnivores, which feed on both plants and animals, and most complex in herbivores, which feed principally on the fibrous portions of plants. See also: Adaptation (biology); Animal evolution; Energy metabolism; Enzyme; Food; Nutrition; Physiological ecology (animal)
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information